1. Field of the Invention
The present invention relates to a novel polymer dispersion which is useful as a mordant for dyes used in photographic systems and to a photographic system containing a layer of this polymer dispersion.
2. Description of the Prior Art
It has heretofore been known in the photographic art to provide a layer which absorbs excess light in a photographic material in order to prevent halation and improve the sharpness of the resulting image. For example, it is known to provide an antihalation layer beneath the support, to provide an antihalation layer between the support and a light-sensitive layer, to provide an antihalation layer(s) between light-sensitive layers, etc.
These antihalation layers and anti-irradiation layers generally contain light-absorbing materials such as dyes, carbon black, colloidal silver, etc. However, these materials when used in a photosensitive layer or a layer adjacent to a photosensitive layer adversely affect photographic properties. For example, they cause desensitization, increase fogging, etc. In other words, when an antihalation layer containing a dye is provided adjacent a photosensitive layer, the dye by diffusion into the photosensitive layer absorbs the light necessary for exposure and thus brings about desensitization. When colloidal silver is used it increases fogging in the adjacent photosensitive layer.
In order to prevent the deterioration of photographic properties by such dye diffusion, a technique has been developed to prevent diffusion by mordanting the dye using various polymers as dye mordants. However, when the polymer mordants described in, e.g., U.S. Pat. No. 2,326,057, etc., are added to an antihalation layer or an anti-irradiation layer to prevent dye diffusion, the adhesion with the adjacent emulsion layer deteriorates remarkably, which sometimes results in peeling of coated layers under conditions such as encountered during development, etc. Further, polymer mordants having a guanylhydrazone of a keto group structure such as described in, e.g., U.S. Pat. Nos. 2,882,156 and 3,740,228, Japanese Patent Publication No. 15820/1974, etc., require a large amount of organic solvent for their production which in turn complicates their use. The mordants of this type also deteriorate adhesion with the adjacent emulsion layer, if used in a large amount to prevent the diffusion of dye.
In multilayered photographic systems, the adhesion between layers is extremely important, and as a result there has been a demand for the development of a mordant which has excellent mordant properties and, at the same time, does not deteriorate the adhesion between layers when incorporated in a photographic system which can be produced easily.
A mordanted dye must be fixed in a photographic material before a development processing and, also, the mordanted dye must be removed out from the photographic material into a development processing solution during a development processing. Because, if the dye remains in the photographic material after the development processing, the dye causes stain in the resulting processed photographic material. However, polymer mordants described in U.S. Pat. No. 3,958,995 strongly mordant the dye during the development processing and, thus, the dye is not substantially removed out from the photographic material into the processing solution. Thus, in the case of the polymer mordants above, it is necessary to decolorize the dye during the development processing, although it is impossible to completely decolorize the dye during the development processing. Thus, it has been damanded to obtain a mordant which is capable of fixing a dye in a photographic material before development processing and capable of removing the dye during the development processing.